Christine Said:

How to learn to sing well enough for a school musical?

We Answered:

sing along with real songs. That how i learend to sing - chorus didn't help me at all. I already knew how to read music from guitar and I could sing.
if you really like a song that is ur level of singing, just play it and sing along.
If you play an instrument that doesnt involve your mouth, sing a note and play it at the same time to get the right pitch. When i play guitar chords, i can almost always hear a note that sounds like what I'm singing.